Good question - though the estate would have to come down on the seller, not Saul & co - the astute follower will have noticed that they have even removed Tolkien from their own business name (Middle-earth Enterprises, used to be Tolkien Enterprises). http://www.middleearth.com/about.html

In wrangling with the Estate over the years, it is clear that they do not have rights to anything "Tolkien".